backend/src/main/java/nju/seec/helper/aspect/event/EventAspect.java

package nju.seec.helper.aspect.event;

import com.google.common.collect.ImmutableMap;
import lombok.SneakyThrows;
import nju.seec.helper.sys.dataanalysis.api.EventApi;
import nju.seec.helper.sys.dataanalysis.constant.EventAction;
import nju.seec.helper.sys.dataanalysis.constant.EventType;
import nju.seec.helper.aspect.auth.LoginUser;
import nju.seec.helper.dao.CourseDAO;
import nju.seec.helper.dao.QuizDAO;
import nju.seec.helper.dto.comment.CommentDTO;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.Aspect;
import org.springframework.stereotype.Component;
import org.springframework.transaction.annotation.Transactional;

import java.time.LocalDateTime;
import java.util.Collections;
import java.util.Map;
import java.util.Objects;
import java.util.stream.Stream;

/**
 * @author cst
 */
@Aspect
@Component
public class EventAspect {
    private final Map<EventType, Map<EventAction, EventHandler>> eventHandleMap;

    public EventAspect(CourseDAO courseDAO, QuizDAO quizDAO, EventApi eventApi) {
        this.eventHandleMap = ImmutableMap.of(
                EventType.LESSON, ImmutableMap.of(
                        EventAction.PARTICIPATE, ((joinPoint, user) -> Stream.of(joinPoint.getArgs())
                                .filter(o -> o instanceof Long)
                                .map(o -> (Long) o)
                                .findFirst()
                                .ifPresent(courseId ->
                                        eventApi.reportEvent(eventApi.createParticipateClassEventDTO(String.valueOf(user.getPid()), LocalDateTime.now(), courseDAO.findCourseById(courseId)))
                                )))
                , EventType.POST, ImmutableMap.of(
                        EventAction.INITIATE, ((joinPoint, user) -> Stream.of(joinPoint.getArgs())
                                .filter(o -> o instanceof CommentDTO)
                                .map(o -> (CommentDTO) o)
                                .findFirst()
                                .ifPresent(commentDTO ->
                                        eventApi.reportEvent(eventApi.createInitPostEventDTO(String.valueOf(user.getPid()), LocalDateTime.now(), Objects.requireNonNull(commentDTO).getTitle()))
                                )))
                , EventType.QUIZ, ImmutableMap.of(
                        EventAction.COMPLETE, ((joinPoint, user) -> Stream.of(joinPoint.getArgs())
                                .filter(o -> o instanceof Long)
                                .map(o -> (Long) o)
                                .findFirst()
                                .ifPresent(quizId ->
                                        eventApi.reportEvent(eventApi.createCompleteQuizEventDTO(String.valueOf(user.getPid()), LocalDateTime.now(), quizDAO.findQuizById(quizId)))
                                )))
        );
    }

    @FunctionalInterface
    private interface EventHandler {
        /**
         * 处理事件
         *
         * @param joinPoint 插入点
         * @param user      登录用户
         */
        void handleEvent(JoinPoint joinPoint, LoginUser user);
    }

    private final EventHandler doNothing = (joinPoint, user) -> {
    };

    @Transactional(readOnly = true)
    @SneakyThrows
    @AfterReturning("@annotation(event) && args(user,..)")
    public void reportEvent(JoinPoint joinPoint, Event event, LoginUser user) {
        eventHandleMap.getOrDefault(event.type(), Collections.emptyMap())
                .getOrDefault(event.action(), doNothing)
                .handleEvent(joinPoint, user);
    }
}